Europium doped caesium bromo iodide scintillator and detectors thereof with improved conversion efficiency
A scintillator includes CsBr x I (1-x) doped with Europium (CsBr x I (1-x) :Eu) wherein x<0.5, and is obtained by annealing CsBr x I (1-x) :Eu material at a temperature from 50° C. to 280° C. The EPR spectrum of the obtained scintillator measured at room temperature at a frequency of 34 GHz shows a maximum signal height at a magnetic field of 1200 mT, and the signal height at 1090 mT and 1140 mT does not exceed 40%, wherein the normalized signal height percentage at 1200 mT is calculated to be 100%. The scintillator is useful in a high energy radiation detection and radiography imaging apparatus.
1. A method of preparing a scintillator including CsI doped with Eu, the method comprising the steps of:
providing CsI:Eu material by mixing CsI with an Eu containing compound; and
annealing by exposing the CsI:Eu material to heat so as to obtain a temperature from 50° C. to 280° C. for at least 5 min.
2. The method according to claim 1 , wherein the CsI is mixed with the Eu containing compound in a melt.
3. A method of preparing a scintillator screen comprising the steps of:
performing the steps of claim 2 ;
pulverizing the CsI:Eu material before the step of annealing;
following the step of annealing, dispersing the pulverized material in a solution including a binder; and
subsequently coating the dispersion on a substrate.
4. The method of preparing a scintillator screen according to claim 3 , further comprising the step of:
exposing the dispersion coated substrate to electromagnetic radiation having a wavelength between 1 pm and 800 nm.
5. The method according to claim 4 , wherein the electromagnetic radiation is UV-light or visible light and has a dose between 10 and 400000 J/m 2 .
6. A method of making a flat panel detector for radiological image detection, the method comprising the steps of:
performing the steps of claim 3 ; and
coupling the scintillator screen to a detector including a plurality of photosensitive elements which convert light into an electric signal.
7. The method according to claim 1 , further comprising the step of:
exposing the annealed CsI:Eu material to electromagnetic radiation having a wavelength between 1 pm and 800 nm.
8. A method of preparing a scintillator screen comprising the steps of:
performing the steps of claim 7 ; wherein
the CsI is mixed with the Eu containing compound in a gas phase; and
the CsI:Eu material is deposited on a substrate via vapour deposition.
9. A method of preparing a flat panel detector for radiological image detection, the method comprising the steps of:
performing the steps of claim 8 ; and
coupling the deposited CsI:Eu material to a detector including a plurality of photosensitive elements which convert light into an electric signal.
10. The method according to claim 9 , wherein the step of exposing is performed before the step of coupling to the detector.
11. The method according to claim 9 , wherein the electromagnetic radiation is UV-light or visible light and has a dose between 10 and 400000 J/m 2 .
12. A method of preparing a scintillator screen comprising the method steps of:
performing the steps of claim 1 ; wherein
the CsI is mixed with the Eu containing compound in a gas phase; and
the CsI:Eu material is deposited on a substrate via vapour deposition.
13. A method of preparing a flat panel detector for radiological image detection, the method comprising the steps of:
performing the steps of claim 12 ; and
coupling the deposited CsI:Eu material to a detector including a plurality of photosensitive elements which convert light into an electric signal.
14. The method according to claim 13 , wherein the step of annealing is performed after the step of coupling to the detector.
15. A method of preparing a scintillator screen comprising the steps of:
performing the steps of claim 1 ;
pulverizing the CsI:Eu material before the step of annealing;
following the step of annealing, dispersing the pulverized material in a solution including a binder; and
subsequently coating the dispersion on a substrate.
16. A method of making a flat panel detector for radiological image detection, the method comprising the steps of:
performing the steps of claim 15 ; and
coupling the scintillator screen to a detector including a plurality of photosensitive elements which convert light into an electric signal.
17. A method of making a high energy radiation detection apparatus, the method comprising the steps of:
performing the steps of claim 1 ; and
coupling the scintillator with a photocathode of a photo multiplier tube.